DE3249342C2 - Device for shaping pipes by surge pressure - Google Patents

Description

a) an impact working chamber between the media separator piston (37) and the impact hammer point of impact (34) is provided with a pulse transmission fluid,

b) the impact working chamber (34) with the molding channel (3) through a media separator piston (37) containing transition piece (36) is connected,

c) a mandrel (6) receiving the tube (7) to be deformed is provided in the channel (3) of the die is, which is mounted lying on a pivotable lever (8) so that it is open when The die (4,5) can be swiveled out of the channel or into the channel,

d) a part (4) of the die is mounted so that it can be swiveled away relative to the other part (5) of the die, and

e) the bandages (13) via a common horizontally displaceable confirmation rod (47) are lockable and unlockable.

2. Device according to claim 1, characterized in that the connection of the transition piece (36) with the horizontally running channel (3) of the die (2) by means of a hydrodynamic hold-down device (40) takes place, the one arranged in the die (2) along the same axis as the axis of the channel (3) Cylinder (49) with an annular base (50), with which it is against the face of the transition piece (36) of the hydraulic percussion unit (24) supports a hollow two-stage piston (51), which in the Cylinder (49) arranged and in which the diameter of its smaller step is the diameter of the Channel (3) of the die (2) is the same, with its face against the face of the tube (7) supports, a connecting bushing (55) with a flange (56), which is inside the transition piece (36) is arranged such that its flange (56) is located inside the cylinder (49) and over the an end face is in contact with the inner surface of the ring base (50) of the cylinder (49), while its other end face with the end face of the piston (51) forms an annular gap (57) which extends to the Axis of the cylinder (49) expanded, as well as one inside the piston (51) and the connecting sleeve (55) contains attached throttle bushing (58) which has radial bores (59) opposite the Annular gap (57) lie.

The invention relates to the shaping, in particular calibration, of pipes by means of liquid surge pressure and relates to a device according to the preamble of claim 1.

In mechanical engineering, there is the problem of precision manufacturing long pipes from difficult to deform Metals and alloys, in particular in the manufacture of roller shells for textile finishing machines and pressure rollers of rotary machines are used. The manufacturing accuracy Very high demands are placed on these pipes, as the rotational speed is increased of rollers or rollers to increase the machine performance intense fluctuations and tearing of the moving material (textile web, paper web). For example, hitting is allowed for the roller shells of textile finishing machines with a roller length of 2200 mm Do not exceed 0.4 mm in size.

There are devices for the production of such pipes are known in which the calibration of the pipes in a Die done by fluid pressure; in particular, from DE-OS 14 52 929 a device for Shaping of pipes by liquid surge pressure of the type mentioned is known in which the longitudinally divided die, which is held together with bandages, is composed of several longitudinal parts, so that a pipe to be deformed can be inserted in the axial direction into the horizontally extending channel got to. The hammer acts on the liquid in the molding chamber via a media separator piston one, but this media separator piston is mounted directly in the wall of part of the die, so that at If the seals on the media separator piston wear out, repairs are hardly possible or they can be replaced of heavily used parts can only be carried out with considerable technical effort can.

The division of the die into several length sections for automation is also very impractical.

From DE-OS 20 26 854 a method and a device for the shaping and calibration of Pipes with a polygonal or circular cross-section known, with the device for implementation of this known method, the die is formed from two half-shells held by two clamps are held together, the design of the half-shells and the internal dimensions of the same being the final Shape and the final external dimensions of the pipe to be produced result. The deformation of the Rohres is carried out here with the help of explosive devices, including a possible edition for the explosives located inside the die.

This known device is also not very suitable for automating the molding operation, since the respective tubes are aligned within the half-shells of the die when the same is inserted have to.

Also known is a device for the calibration of pipes by means of liquid pressure (SU-Urheberschein 3 77 181, published in the bulletin "Discoveries, inventions, designs, trademarks", 1973, No. 18), with which the calibration of pipes is carried out section by section. This facility contains a split die mounted on a frame with a horizontally running calibration channel, which the Corresponds to the pipe shape and in which a mandrel for the

NEN of the pipe is present along the channel axis and means for supplying liquid to the hermetically sealed Gap between mandrel and pipe. In the mandrel are channels for supplying liquid to the gap between Mandrel and tube provided. The die itself is parallel to the mandrel, which is present on the frame mentioned running guides arranged to be displaceable back and forth The displacement of the pipe to successive Calibration is done here with the help of a carriage that has a centering device for one end of the pipe to be calibrated. With the help of the carriage, the pipe is pushed into the die, which is located is in one of its end positions, whereupon the die is closed. The pipe is then put together with the carriage and the die further moved in guides to the other end position of the die, in which on The pipe section to be calibrated and enclosed by the die is pushed onto the mandrel. After that a liquid is supplied to the gap between the mandrel and the pipe and the pipe is daun after reaching plastically deformed at a certain pressure

In such a pipe production from materials solidified during the deformation (for example from Stainless steels) carries out the calibration, which takes place in sections, to pre-consolidate the pipe material on the Boundary between a calibrated and a non-calibrated section This leads to an increase in the degree of unevenness the stresses in the next section of the pipe when it is calibrated arise, whereby the springing of the material is variable at the section boundaries. Through this That fact, the quality of the products is also deteriorated because of the manufacture of precision parts when calibrating by static fluid pressure only taking into account the size of the suspension of the Material after removal of the load is possible.

The calibration, which takes place in sections, cannot precisely route the pipe casing along the Generators result (i.e. correct their curvature), and all the more so that the calibrating part the device - the split die - is moved in guides relative to the fixed mandrel.

The total error also includes the error of the non-parallelism of this shift and various Placing the die in the guides.

The device described has a low work performance, which is caused by multiple use the calibration taking place in sections is required. The total time it took to calibrate a pipe the entire length of which is required is practically so many times greater than the duration of a single one Calibration process for each section, by how many times the pipe length is greater than the length of the calibrating die part is because the calibration of each new pipe section is the repetition all work stages required for the execution of this work process.

In addition, the pipe ends remain uncalibrated because the hermetic sealing of the gap between The mandrel and tube are made on the inside diameter with the help of seals in the annular grooves be accommodated on the mandrel outer surface. These uncalibrated pipe ends either have to be cut off (which leads to a higher material consumption), or the remaining ones must Any other way of eliminating imperfections.

The invention is based on the object of a device for shaping rings by means of liquid surge pressure to create the specified genus, which with ease of use and the possibility automation to improve the quality of the pipe calibration.

This task is based on the generic Device achieved by the features listed in the characterizing part of claim 1.

To improve the calibration quality of the

ίο the pipe ends is expediently the connection of the transition piece with the horizontally running channel of the die by means of a hydrodynamic hold-down device made, the one in the die along the same axis as the axis of said channel arranged cylinder with a ring base, with which he is against the face of the transition piece of the hydraulic impact unit supports, a hollow two-stage piston arranged in a cylinder which the diameter of the smaller step is equal to the diameter of the calibration channel of the die and which is supported with its end face against the end face of the pipe, a connecting socket with a Flange which is arranged inside the transition piece so that its flange is inside the cylinder and is in contact via one end face with the inner surface of the cylinder base, meanwhile the other face forms an annular gap with the piston face, which widens in the cylinder axis, and includes a throttle sleeve disposed inside the piston and the connecting sleeve and has radial bores which lie opposite the annular gap.

The calibration of pipes in one operation over the entire pipe length is made possible by application a hydraulic impact unit technologically enabled, which represents a high-energy source. The secured one Gap between the tube and the inner diameter of the die allows it to be in front of the immediate Calibration on the die surface completely transforms the material to be deformed into the plastic Include high-speed forming, which involves exerting high pressures on the pipe as a result of the action occurs from impact waves, which creates a favorable state of stress in the deformation zone. This not only improves the sliding conditions in the metal and increases the plasticity of most metals (including stainless steels, titanium alloys and other materials that are difficult to deform), but is the same also the stresses in the pipe cross-section. This eliminates the adverse influence of the defects in the metal local weakened spots and conditions for the springing of the metal become practical abolished. As the pipe hits the die wall at a high velocity, the pipe material experiences a very high braking acceleration which, according to its size, has considerable inertia additions to the stresses results that arise in the metal under the action of external compressive forces. This condition in the final stage of the process creates conditions for plastic material flow in both macro and micro volumes. As a result of such calibration, the outer surface of the pipe becomes an exact copy of the inner lines of the die.

The invention is explained below using the description of a specific exemplary embodiment thereof with reference to the drawings; in the drawings shows
F i g. 1 - the overall view of an inventive

ßen device for the calibration of pipes in the Position before calibration (in longitudinal section);

F i g. 2 - a device according to the invention for calibration of pipes in section along the line II-II of Fig. i;

Fig.3 - a section along the line III-III of Fig. 2;

Fig.4 - a hydrodynamic according to the invention Hold-down device on an enlarged scale (in longitudinal section).

The device for calibrating pipes by liquid pressure includes a device on a frame 1 (Fig. 1) assembled split die 2 with a lock. The die 2 has a horizontally running calibration channel 3, which corresponds in its shape to the tubular shape and by an upper die half 4 and a lower die half 5 is formed on.

The device also includes a mandrel 6 for placing a tube 7 along the axis of the calibration channel 3. The mandrel 6 is attached overhung to a lever 8 at one of its ends. The pipe 7 is in the Die 2 arranged on the mandrel 6 so that a gap 9 between the outer surface of the tube 7 and the surface of the calibration channel 3 and a gap 10 between the inner surface of the tube 7 and the surface of the Doms 6 exist. To center the tube 7 relative to the mandrel 6 and the die 2 is at the free end of the Doms 6 a pair of pliers 11 attached.

The lower die half 5 is fixedly attached to the frame 1 via a chock 12, while the upper die half 4 is connected to moving parts of the lock that closes the abutment surface between the die halves 4 and 5 is determined. The lock contains brackets 13, which are held by a plate 14 are connected to one another, as well as wedges 15, which are connected to hydraulic drive cylinders (not shown in FIG. 1) are kinematically connected, which are located between the upper die half 4 and the plate 4 are located in the spaces between the brackets 13.

To supply liquid to the gap 10 between the dome 6 and the tube 7 are in the mandrel 6 and in Lever 8 channels 16, 17 are provided with a check valve 18, which is connected to a (not shown in FIG. 1) Liquid container are in communication.

To hermetically seal the gap 10 between the pipe 7 and the mandrel 6, the calibration channel 3 seals 19 are provided, which are attached to the end faces of the tube 7.

To press the tube 7 against the seals 19, a bracket 20 attached to the frame 1 is provided Wedge 21 attached

To return the dome 6 to the starting position isi between the lever 8 and the collar 22 of the Doms 6 a spring 23 is arranged

To generate a liquid pressure in the gap 10 between the mandrel 6 and the pipe 7, the device contains for the calibration of pipes a hydraulic impact unit 24, which includes a cylindrical barrel 25 in which a firing pin 26 is housed, one starter 27 and one (not shown in FIG. 1) Means for returning the firing pin 26 to the upper end position, d. H. Starting position owns this Means is usually designed as a hydraulic pump for locking the firing pin 26 in the upper In the end position, a pair of pliers 29 is attached to a cover 28. The cylindrical barrel 25 is from a pressure vessel 30 surrounded with pressurized gas. For overflowing the pressurized gas from the pressure vessel 30 into a cavity 31, which is located above the firing pin 26, is a channel 32 and a valve 33 of the starter in the cover 28 27 provided.

The hydraulic percussion unit 24 also contains a working chamber 34, which is in the form of a curved Channel is formed in a solid metal housing 35. The interior of the working chamber 34 is with a Liquid filled as operating medium, in the event of an impact carried out by the firing pin 26 for calibration fluid pressure required by pipes is generated. The working chamber 34 is with the calibration channel 3 is connected to the die 2 by means of a transition piece 36. To separate the liquid that the working chamber 34 of the hydraulic percussion unit 24 fills, from the liquid that the gap 10 between the mandrel 6 and the tube 7 is fed, a piston 37 is arranged in the transition piece 36, wherein a coolant used in the clamping molding as the liquid supplied to the gap 10 and oil as Liquid is used to fill the working chamber 34.

To supply pressure from the hydraulic pump (not shown in FIG. 1) to a sub-hydraulic pump Firing pin 26 lying cavity 38 for the purpose of returning this firing pin 26 to its starting position a channel 39 is implemented in the housing 35 of the working chamber 34.

For hermetically sealing the gap between the mandrel 6 and the tube 7 during the deformation the same in addition to simultaneously sealing the abutment surface between the hydraulic impact unit 24 and a hydrodynamic hold-down 40 is used for the die 2.

On the frame 1 on both sides of the die 2 eyelets 41 (Fig. 2, 3) and 42 are present, which go through in pairs Rods 43 are attached. The brackets 13 are with the eyelets 41 by means of axes 44 with the possibility of a Swiveling through an angle of 90 ° and connected with hydraulic cylinders (not shown in FIG. 2) Kinematically connected to arrange the die half 4 on the die half 5. To connect the clamps 13 with the eyelets 42 are provided with pins 45 which are attached to a movable rod 47 by means of cantilever arms 46 are attached, which is moved by a hydraulic cylinder (not shown in FIG. 2).

In the position turned by 90 °, the bracket 13 is indicated by a dot-dash line.
The lever 8 (indicated by a dash-dotted line in FIG. 2 in the turned position) can, for the purpose of introducing the dome 6 with the tube 7 into the die 2, at an angle of = 135 ° around an axis which coincides with the axis of the pins 45 coincides to be pivoted.

A connecting mass in the form of metal blocks can be attached to the plate 14 between the clamps 13 48 for damping overloads caused by inertia, which are transmitted to the die half 4 via the tube 7 will be arranged.

The hydrodynamic hold-down 40 contains one in the die 2 along one and the same axis as the Axis of the calibration channel 3 arranged cylinder 49 (FIG. 4) with an annular base 50. The inner diameter this cylinder 49 is larger than the diameter of the calibration channel 3. The bottom 50 is supported on Transition piece 36 of the hydraulic impact unit 24 from. Inside the cylinder 49 is a hollow two-stage Piston 51 arranged in which the stage with the small

neren diameter goes into the calibration channel 3 and a sealing ring 19 against the end face of the pipe 7 is supported. A ring 52 is provided to hermetically seal the interior of the cylinder 49 Rubber seals 53 and 54 are provided. The hydrodynamic hold-down 40 also closes a connecting socket 55 with a flange 56 which is mounted inside the transition piece 36 so that you Flange 56 is located in the interior of the cylinder 49 and over one end face with the inner surface of the base 50 of the cylinder 49 is in contact while the other The end face of the flange 56 with the end face of the piston 51 forms an annular gap 57 which extends to the axis of the Cylinder 49 expanded.

In the interior of the piston 51 and the bushing 55, a throttle bushing 58 with radial bores 59 is attached, which lie opposite the gap 57.

To compensate for the misalignment of the transition piece 36 of the hydraulic impact unit 24 and the calibration channel 3 and to avoid breakage of the hydrodynamic hold-down 40 at the moment the impact carried out by the firing pin 26 on the liquid filling the working chamber 34, in which the hydraulic impact unit 24 is displaced relative to the die 2 is between the cylinder 49 and the flange 56 has a recess 60, while the throttle bushing 58 support collars 61 with toroidal Has surface.

The device for calibrating pipes is working in the following way.

The upper half of the die is in the starting position 4 (F i g. 1,2) with the plate 14, the wedges 15, the brackets 13 around the axis 44 clockwise around one Turned 90 °, and the Do-n 6 is in the service area transferred by turning the lever 8 counterclockwise.

In this position, the pipe 7 is pushed onto the mandrel 6, after which the mandrel 6 with the pipe 7 in a clockwise direction rotated and attached concentrically in the lower die half 5, whereupon he with the upper Die half 4 is covered, with which the clamps 13, the plate 4 and the wedges 15 move. The movable pins 45 (Fig. 3) attached to the cantilever arms 46 are slid the rod 47 is inserted into the openings of the clamps 13, after which the die halves 4 and 5 pressed together by means of the wedges 15 (Fig. 1, 2), the mandrel 6 is then pressed on with the wedge 21 so that the tube 7 is sealed at its end faces will. Then a system of channels 16, 17 via the check valve 18, the gap 10 between the mandrel 6 and the tube 7 a liquid (z. B. a cooling emulsion) is supplied, which also into the interior of the transition piece 36 of the hydraulic impact unit 24 flows and the piston 37 here in the right Pushes away end position.

To carry out the calibration operation, the valve 33 is raised by means of the starter 27, wherein the air contained in the pressure vessel 30 enters the cavity 31 above the firing pin 26 and hits it on a high speed (50-100 m / sec) accelerated. The firing pin 26 delivers a blow to the liquid present in the working chamber 34 and generates it therein a high pulse pressure, which is transmitted via the piston 37 to the liquid which forms the gap 10 between the mandrel 6 and the tube 7 fills

The plastic deformation of the material of the tube 7 and the calibration of its outer surface on the die 2 takes place through the pressure pulse generated in the liquid, in that it acts on the tube 7 from the inside. Through the bores 59 and the annular gap 57, the liquid pressure also acts on the face of the hollow two-stage piston 5 t by moving it following the end face of the tube 7, its length decreases during its calibration with accompanying expansion. This leaves the seals in place always pressed against the end faces of the tube 7, resulting in a hermetic seal of the abutment surface between the mandrel 6 and the tube 7 guaranteed.

After the calibration has been carried out, the wedges 21 and 15 are brought out with the aid of hydraulic cylinders. The die halves 4 and 5 and the mandrel 6 are released, which under the action the spring 23 is returned to the starting position. At the same time, compressed air is the interior of the Cylinder 49 fed between the ring 52 and the piston 51, causing the piston 51 to the right into the Starting position (until it rests on the flange 56) is pushed so that the piston 51 out of contact comes with the pipe 7 and does not prevent it from being led out through the mandrel 6 into the service zone. Thereafter, the pins 45 are guided out of the clamps 13, and the upper die half 4 is rotated clockwise, while the mandrel 6 with the fully calibrated pipe 7 is pivoted out into the operating zone 6 is where the pipe 7 is tightened and a next pipe 7 is pushed in its place.

At the same time as the die 2 is opened and the mandrel 6 with the tube 7 is removed, the return takes place of the firing pin 26 in the starting position (upper end position). This is done by the hydraulic Pump the operating fluid supplied to the channel 39, which fluid lifts the firing pin 26, so that the compressed gas expanded in the interior of the cylindrical barrel 25 is displaced into the pressure vessel 30. To The valve 33 is reached with the aid of the starter 27 by the firing pin 26 lowered and the inlet cross-section of the cylindrical barrel 25 blocked, whereby the cylindrical barrel 25 is separated from the pressure vessel 30. The firing pin 26 is secured at the top with the pliers 29. After that flows the operating fluid is discharged into a container via the channel 39. The facility is about to run a next Duty cycle ready.

The use of a pipe calibration device of the construction described above allows pipes to be calibrated with a high degree of accuracy. An experimental test on a laboratory system showed that the accuracy of the calibrated products practically depends on the accuracy of the die production is predetermined For example, when calibrating a pipe with a diameter of 102 χ 2 mm and a length of 1000 mm made of stainless steel, the curvature of the pipe producing 0.01 mm, the accuracy of the diametrical mass being determined by the surface roughness. Same Curvilinear was found in the generatrix of the inner surface of the die.

The calibration of a pipe in one operation over the entire length of the same with mechanized Feeding the tube to the die and also mechanized output of the finished product into the The service zone allowed the time required to calibrate a pipe to be reduced significantly. The time taken to perform an operation from attaching the tube to the mandrel and until it is removed

me of the finished product of the same
lake.

For this purpose 3 sheets of drawings

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Claims (1)

Patent claims: 1. Device for shaping pipes by liquid surge pressure, with a longitudinally divided and die held together with bandages with a horizontally running channel for the nominal shape of the Pipe, with a secured by a check valve feed pipe for the hydraulic fluid to Filling the mold space with a hammer driven by a pressure fluid, which has a Media separator piston acts on the liquid in the molding chamber, with sealing sleeves for both pipe ends, the sealing effect of which is reinforced by the pressure of the forming fluid is characterized in that